Rotary unions or joints are employed to interconnect rotative fluid systems with fixed conduits, i.e. in rotary driven heating or cooling systems. Such unions normally include relatively movable seals wherein wear occurs at the seal faces requiring periodic maintenance.
Known rotary unions and joints are often difficult to disassemble for maintenance, and it is a purpose of the invention to provide a rotary joint particularly characterized by its ease of assembly and maintenance and efficient sealing.
Another object of the invention is to provide a rotary union or joint employing anti-friction bearings wherein a retainer accurately positions the bearings upon an annular support conduit or sleeve, and the retainer includes a seal having a radial face whereby the retainer performs a dual purpose.
A further object of the invention is to provide an efficient, self-aligning rotary joint having vents to accommodate leakage, and wherein relatively engagable seals are positioned to resist relative rotation, but are capable of readily accommodating misalignment during rotation.
An additional object of the invention is to provide a rotary joint employing engagable annular seals wherein the seals are maintained in contact by a compression spring acting upon a seal assembly which simultaneously seals rotating seal structure to a fixed seal housing.
In the practice of the invention an annular conduit in the form of a sleeve includes a supporting flange for attachment of the joint to the rotating member, such as a heating or drying drum. Anti-friction bearings are mounted upon the sleeve within a bearing housing, and an annular bearing retainer threaded upon the end of the sleeve engages the bearings to axially position the same thereon and the retainer includes a seat for coaxially supporting an annular seal having a radial sealing face.
A seal housing is removably attached to the end of the bearing housing by bolts, and the seal housing includes at least one port for attachment of a conduit thereto in communication with the interior of the seal housing and the sleeve. An annular seal retainer is loosely supported within the seal housing upon axially extending pins, and an annular seal having a radial face is supported upon the retainer for engagement with the bearing retainer supported seal. A seal assembly biased toward the sleeve by a compression spring located within the seal housing imposes an axial force upon the seal retainer and supported seal, and simultaneously seals the retainer relative to the seal housing. This relationship is accomplished by the presence of radially extending surfaces defined on the seal assembly and the seal retainer permitting axial forces to be imposed on the seal retainer by the assembly.
Vents defined in the bearing housing in radial alignment with the relatively moving seal faces permit lost fluid to readily escape without the buildup of pressure, and the axial biasing forces imposed upon the seal assembly and seal retainer permit self-alignment of the relatively moving seal surfaces due to the loose support of the seal retainer, even though this support does not permit relative rotation with respect to the seal housing.
Apparatus constructed in accord with the invention may be economically manufactured and readily assembled, and the objects sought to be achieved by the invention are met.